Airborne platforms such as, for example, kites, balloons, and blimps, may be used to suspend instrumentation above the earth's surface. Such airborne platforms may be favored because they are inexpensive, light in weight, portable, and easy to deploy. The instrumentation suspended from the airborne platforms may include, for example, imaging devices and various sensors. Particularly for imaging devices, it may be important to stabilize the instrumentation as much as possible.
The airborne platforms may include a line or tether that may have one end fixed to the airborne platform and the other end fixed to a control point on the ground, such as a winch or a human being. FIG. 1 shows an airborne platform 10 fixed to a tether 12. The tether 12 may be connected to a winch 14 located on an operating surface 16. The airborne platform 10 may be, for example, a kite, balloon, blimp, etc. The operating surface 16 may be the ground or a structure on the ground or water. The tether 12 may be used to suspend instrumentation (not shown in FIG. 1) above the surface 16.
The Picavet suspension system (named after Pierre L. Picavet) is a traditional method for suspending cameras from kite lines. The Picavet system uses a pulley and line arrangement to level an instrument platform and reduce the pointing motion during flight of a kite. The bridle line of the Picavet system may be prone to tangling. In addition, the Picavet system includes several moving parts that may jam or otherwise fail.
Vaisala (Boulder, Colo., USA) manufactures a TetherSonde System for tethered blimps. The TetherSonde System incorporates a mounting technique that translates tether motion directly to the instrument. Translating the tether motion directly to the instrument may result in undesirable movement of the instrument. The TetherSonde system may require a complex moving part in the form of a pivot attachment.
A need exists for a suspension apparatus for instrumentation that is light-weight and simple to construct, while providing the stability needed for the instrumentation.